Examine source code of Bubble Game

{
  "name": "Bubble Game",
  "version": "3.0",
  "manifest_version": 2,
  "description": "you can play game directly from the sidebar!",
  "permissions": [
    "tabs",
    "<all_urls>"
  ],
  "browser_action": {
    "default_title": "Side Games - play side panel mini games",
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "sidebar_action": {
    "default_title": "Side Games",
    "default_panel": "sidebar.html",
    "default_icon": "icon.png"
  },
  "applications": {},
  "browser_specific_settings": {
    "gecko": {
      "id": "{f64451a8-4cb4-4265-bbd2-15c1ba15b13a}"
    }
  }
}